1. Field of the Invention
This method relates to electronic systems, and more particularly, to methods of cooling electronic systems.
2. Description of the Related Art
One important aspect in the design of computers and other electronic systems is controlling the transfer of heat from heat-generating components in order to prevent these components from overheating. The inability to prevent overheating of such components can lead to erroneous operation, and if severe enough, failure of these components. This is particularly true for various types of integrated circuits and multi-chip modules. Traditional methods for transferring heat electronic systems include the use of heat sinks and fans.
One alternative to the traditional methods for heat transfer in electronic systems is the use of heat pipes mounted on components that generate a significant amount of heat. A heat pipe is a hollow cylinder that is at least partially filled with a vaporizable liquid. FIG. 1 illustrates the operation of one embodiment of a heat pipe. When the component to which the heat pipe is mounted generates enough heat, the liquid in the heat pipe absorbs this heat and thus causes its temperature to rise. When the temperature of the liquid reaches its boiling point, at least some of the liquid boils into a vapor phase. The vapor then rises into the upper portion of the heat pipe, where some of the heat is released. When enough of the heat is released, the vapor condenses and returns to a liquid state and returns to the lower portion of the heat pipe. This cycle repeats itself as long as the component to which the heat pipe is mounted generates a sufficient amount of heat. In this manner, a heat pipe can continuously transfer heat away from the component to which it is mounted. 
One of the problems in mounting heat transfer devices such as heat pipes to electronic components involves ensuring sufficient contact. It is often times difficult to completely eliminate gaps between the surface of a heat transfer device and the device to which it is to be mounted (e.g., an integrated circuit package). This is because it is difficult to make the surface of such a component entirely flat. Since air is a very poor conductor of heat, any air gaps between the heat transfer device and its associated component can significantly reduce its effectiveness. While certain materials are available that can be used to eliminate the air gaps, these materials may not be as effective in transferring heat from the surface of the component to the heat transfer device. Thus, the inability to control the surface contact (as well as the inability to control the surface contact pressure) may reduce the effectiveness of heat transfer devices such as heat pipes. 